Chinese Coast Guard officials blocked a group of Filipino fisherman from entering the Scarborough Shoal in the South China Sea after an international court ruled this week that Beijing does not have valid claims to the disputed region rich in seafood and gas reserves.

The Filipino fisherman were traveling with a news team from ABS-CBN, a Filipino television network. They were first followed by a Chinese fishing vessel that tried to block them from entering the area around Scarborough Shoal. The Chinese Coast Guard at one point showed up and ordered the Filipino fishermen to leave the area, according to media reports Thursday.

An international tribunal in The Hague blasted Tuesday China’s construction of artificial islands in the South China Sea in an unprecedented case brought by the Philippines. Brunei, Indonesia, Malaysia, Taiwan and Vietnam have also rejected China’s claims that it enjoys historic rights over most of the South China Sea.

Chinese President Xi Jinping said the ruling was not legally binding and insisted China’s claim to sovereignty over the South China Sea can be traced to “ancient times.” The tribunal’s decision “is invalid and has no binding force,” the government said in a statement. “China does not accept or recognize it.”

The United States urged China to accept the decision. “The world is watching to see if China is really the global power it professes itself to be and the responsible power that it professes itself to be,” said State Department spokesman John Kirby.

The Philippines and the United States are eager to limit China’s ambitions in the South China Sea while avoiding military conflict. The Scarborough Shoal is considered an important strategic zone because of its proximity to the coast of the Philippines, a U.S. ally.

“In the aftermath of the court decision, China likely will test the U.S.’ readiness to uphold the rules, creating military provocations that could escalate into war,” Kori Schake, a research fellow at Stanford University’s Hoover Institution in California, wrote in a Thursday op-ed in the Los Angeles Times.

Supreme Court Associate Justice Francis Jardeleza warned Filipino fishermen Wednesday to remain cautious when fishing along the Scarborough Shoal. He urged local governments to take action to protect the fishermen who depend on the Scarborough Shoal for their livelihood, according to local media reports.

“It is important that the local government should reach out to the local fishermen. There has to be a clearguide, safeguards for their protection,” Jardeleza said.